Flat wire conveyor belts have been in the market for many years. Flat wire conveyor belts are generally low maintenance and when positively driven with sprockets have little to no lateral shifting. With reference to FIG. 1, U.S. Pat. No. 2,619,306 discloses a flat wire conveyor belt 10 comprising a plurality of pickets 16, sometimes also referred to as wickets, and interconnecting rods 18 about which the pickets hinge. The pickets 16 on belt 10 support the product to be conveyed and the rods 18 are utilized to hold the components of belt 10 together.
In a straight run, when a sprocket tooth is disposed within an opening defined by a link in the picket, the sprocket tooth relieves the tension in the adjacent pickets and concentrates it one location, thereby causing rod 18 to deflect at the sprocket tooth. This in turn causes the link in the picket which surrounds the sprocket tooth to become more highly loaded. Hence, fatigue and breakage may occur at one or more of the link areas surrounding a sprocket tooth where rod 18 meets picket 16.
Fatigue breakage at one or more of the picket areas of a flat wire conveyor belt is a function of the number of cycles that a particular area is flexed. This problem becomes even more pronounced as the conveyor belt becomes lighter in weight and more open.
U.S. Pat. No. 5,950,807 is a light duty conveyor belt constructed from round wire elements that only partially hinge and thereby flex due to interferences between the wire elements. The '807 patent attempts to increase load carrying ability of the conveyor belt without increasing weight by using alternating small and large openings in the belt. While this may marginally improve the strength of the belt, the belt still experiences rapid failure because of the inability of the wire elements to truly binge freely, and the belt still has a tendency to deflect when driven by sprockets which imparts fatigue loading to the wire elements, resulting in wire breakage.
Accordingly, there exists a need in the marketplace for a flat wire conveyor belt having a lighter weight and reduced quantity of required material; thus reducing the cost, while still retaining its strength so as to avoid fatigue failure.